The Effect of Farm Labor Organization on IPM Adoption: Empirical Evidence from Thailand

This paper examines the empirical evidence of a theoretical economic model of the effect of labor organization on IPM adoption developed by Beckmann and Wes seler (2003). We use cross section data collected from the participatory farming system survey of 150 durian growers in Chanthaburi, Thailand, on March April 2005. In contrast to many studies of IPM adoption, this work uses the form of farm labor organiza tion as endogenous factor for identifying the rate of IPM adoption of durian growers. Instrumental variables method was employed to relate econometrically a set of suspected variables as instruments of labor organization to the rate of IPM adoption of duri an growers. Results show that, among others, farms employing hired labor have a lower adoption rate of IPM, which supports the theoretical model.Labor Organization, IPM Adoption, IV -Tobit, Farm labor, Agricultural Extension, Farm Management, Labor and Human Capital, Q16, J2, J43,

Algebraic Methods of Classifying Directed Graphical Models

Directed acyclic graphical models (DAGs) are often used to describe common structural properties in a family of probability distributions. This paper addresses the question of classifying DAGs up to an isomorphism. By considering Gaussian densities, the question reduces to verifying equality of certain algebraic varieties. A question of computing equations for these varieties has been previously raised in the literature. Here it is shown that the most natural method adds spurious components with singular principal minors, proving a conjecture of Sullivant. This characterization is used to establish an algebraic criterion for isomorphism, and to provide a randomized algorithm for checking that criterion. Results are applied to produce a list of the isomorphism classes of tree models on 4,5, and 6 nodes. Finally, some evidence is provided to show that projectivized DAG varieties contain useful information in the sense that their relative embedding is closely related to efficient inference

How peoples' ratings of dental implant treatment change over time

Objectives: Dental implant treatment (DIT) improves peoples’ oral health-related quality of life (OHQoL). Assessment of changes in OHRQoL may be undermined by response shift (RS). RS is the process by which quality of life change, independent of health status as a result recalibration, reprioritization or reconceptualization. Thus, this research aimed to identify RS in individuals receiving dental implant treatment and to determine the validity of three approaches to measure it; the then-test, the self-anchored scale and the classification and regression trees (CRT). Methods: OHRQoL was assessed in 100 patients receiving DIT using the OHIP-Edent and the self-anchored scale before placement of the final restoration and 3 to 6 months after the treatment was completed. The OHIP-Edent was also used as a retrospective assessment at the follow-up. CRT examined changes in the OHIP-Edent total score as a dependent variable with global changes in oral health and each OHIP-Edent subscale score as independent variables. Results: OHRQoL improved after treatment. The OHIP-Edent score decreased from 36.4 at baseline to 12.7 after treatment. On average participants recalibrated their internal standard downwards (-4.0 OHIP-Edent points). The CRT detected recalibration (5% downwards and 15% upwards). Reprioritization was observed among the social disability and psychological discomfort aspects of OHRQoL. Conclusions: RS affects longitudinal assessments of OHRQoL in DIT reducing the apparent magnitude of change. Results of this study identified then-test and the CRT as valid complementary methods to assess RS

Semantic Domains and Denotational Semantics

The theory of domains was established in order to have appropriate spaces on which to define semantic functions for the denotational approach to programming-language semantics. There were two needs: first, there had to be spaces of several different types available to mirror both the type distinctions in the languages and also to allow for different kinds of semantical constructs - especially in dealing with languages with side effects; and second, the theory had to account for computability properties of functions - if the theory was going to be realistic. The first need is complicated by the fact that types can be both compound (or made up from other types) and recursive (or self-referential), and that a high-level language of types and a suitable semantics of types is required to explain what is going on. The second need is complicated by these complications of the semantical definitions and the fact that it has to be checked that the level of abstraction reached still allows a precise definition of computability

Rest, Sweet Nymphs: Pastoral Origins of the English Madrigal

This thesis is an interdisciplinary study of the impact pastoral themes in art, literature, and music had on the stylistic and thematic development of the late-Renaissance English madrigal (ca. 1590–1620), specifically works by Elizabethan composers. Madrigals were profoundly influenced by poetry and visual art as the basis for text and subject matter. Consequently, many English madrigals, both light and serious forms, cultivated Arcadian themes presented in Italian idyllic art and literature of the late-fifteenth and early-sixteenth centuries. Works discussed throughout each chapter include Jacopo Sannazaro’s poetic collection, Arcadia (ca. 1489), Edmund Spenser’s seasonal eclogues, The Shepheardes Calender (1579), Oliver Isaac’s portrait of Elizabeth I and the Three Goddesses (ca. 1590), Francis Pilkington’s madrigal “Rest, Sweet Nymphs” (1605), and Thomas Tomkin’s ballett “See, See the Shepherds’ Queen” (1622), among others. Analyses of rustic imagery, such as landscape, allegory, and expressive tone, in individual works draw thematic connections between pastoral repertoires throughout Europe, which affected the English pastoral tradition